Improvements and fixes to Cycles metadata

This is a request by the studio here to make it possible to see how
many samples were used to render a specific shot or a frame. It is a
bit more tricky than simply stamping number of samples from a scene
since rendering is happening in multiple ranges of samples.

This change makes it so Cycles saves configured number of samples for
the specific view layer, and also stores start sample and number of
samples when rendering only a subrange of all samples.

The format used is "cycles.<view_layer_name>.><field>", which allows
to have information about all layers in a multi-layer EXR file.

Ideally we can store simplified "cycles.<field>" if we know that there
is only one render layer in the file, but detecting this is somewhat
tricky since Cycles operates on an evaluated scene which always have
single view layer.

The metadata is shown in the Metadata panels for clip, image and
sequencer spaces.

Example screenshot which shows the metadata:

{F6527727}

Reviewers: brecht

Reviewed By: brecht

Subscribers: fsiddi

Differential Revision: https://developer.blender.org/D4311

intern/cycles/blender/blender_session.cpp

@@ -393,6 +393,28 @@ static void add_cryptomatte_layer(BL::RenderResult& b_rr, string name, string ma
 	render_add_metadata(b_rr, prefix+"manifest", manifest);
 }
 
+void BlenderSession::stamp_view_layer_metadata_do(const string& prefix)
+{
+	BL::RenderResult b_rr = b_engine.get_result();
+	/* Configured number of samples for the view layer. */
+	b_rr.stamp_data_add_field((prefix + "samples").c_str(),
+	                          to_string(session->params.samples).c_str());
+	/* Store ranged samples information. */
+	if(session->tile_manager.range_num_samples != -1) {
+		b_rr.stamp_data_add_field(
+		        (prefix + "range_start_sample").c_str(),
+		        to_string(session->tile_manager.range_start_sample).c_str());
+		b_rr.stamp_data_add_field(
+		        (prefix + "range_num_samples").c_str(),
+		        to_string(session->tile_manager.range_num_samples).c_str());
+	}
+}
+
+void BlenderSession::stamp_view_layer_metadata(const string& view_layer_name)
+{
+	stamp_view_layer_metadata_do("cycles." + view_layer_name + ".");
+}
+
 void BlenderSession::render(BL::Depsgraph& b_depsgraph_)
 {
 	b_depsgraph = b_depsgraph_;
@@ -408,9 +430,6 @@ void BlenderSession::render(BL::Depsgraph& b_depsgraph_)
 	/* render each layer */
 	BL::ViewLayer b_view_layer = b_depsgraph.view_layer_eval();
 
-	/* We do some special meta attributes when we only have single layer. */
-	const bool is_single_layer = (b_scene.view_layers.length() == 1);
-
 	/* temporary render result to find needed passes and views */
 	BL::RenderResult b_rr = begin_render_result(b_engine, 0, 0, 1, 1, b_view_layer.name().c_str(), NULL);
 	BL::RenderResult::layers_iterator b_single_rlay;
@@ -525,14 +544,7 @@ void BlenderSession::render(BL::Depsgraph& b_depsgraph_)
 			break;
 	}
 
-	if(is_single_layer) {
-		BL::RenderResult b_rr = b_engine.get_result();
-		string num_aa_samples = string_printf("%d", session->params.samples);
-		b_rr.stamp_data_add_field("Cycles Samples", num_aa_samples.c_str());
-		/* TODO(sergey): Report whether we're doing resumable render
-		 * and also start/end sample if so.
-		 */
-	}
+	stamp_view_layer_metadata(b_rlay_name);
 
 	/* Write cryptomatte metadata. */
 	if(scene->film->cryptomatte_passes & CRYPT_OBJECT) {

intern/cycles/blender/blender_session.h

@@ -151,6 +151,9 @@ public:
 	static bool print_render_stats;
 
 protected:
+	void stamp_view_layer_metadata(const string& view_layer_name);
+	void stamp_view_layer_metadata_do(const string& prefix);
+
 	void do_write_update_render_result(BL::RenderResult& b_rr,
 	                                   BL::RenderLayer& b_rlay,
 	                                   RenderTile& rtile,

source/blender/blenkernel/intern/image.c

@@ -2094,6 +2094,24 @@ struct StampData *BKE_stamp_info_from_scene_static(Scene *scene)
 	return stamp_data;
 }
 
+static const char *stamp_metadata_fields[] = {
+	"File",
+	"Note",
+	"Date",
+	"Marker",
+	"Time",
+	"Frame",
+	"FrameRange",
+	"Camera",
+	"Lens",
+	"Scene",
+	"Strip",
+	"RenderTime",
+	"Memory",
+	"Hostname",
+	NULL
+};
+
 void BKE_stamp_info_callback(void *data, struct StampData *stamp_data, StampCallback callback, bool noskip)
 {
 	if ((callback == NULL) || (stamp_data == NULL)) {
@@ -2105,6 +2123,8 @@ void BKE_stamp_info_callback(void *data, struct StampData *stamp_data, StampCall
 		callback(data, value_str, stamp_data->member, sizeof(stamp_data->member)); \
 	} ((void)0)
 
+	/* TODO(sergey): Use stamp_metadata_fields somehow, or make it more generic
+	 * meta information to avoid duplication. */
 	CALL(file, "File");
 	CALL(note, "Note");
 	CALL(date, "Date");
@@ -2177,6 +2197,30 @@ void BKE_imbuf_stamp_info(RenderResult *rr, struct ImBuf *ibuf)
 	BKE_stamp_info_callback(ibuf, stamp_data, metadata_set_field, false);
 }
 
+BLI_INLINE bool metadata_is_copyable(const char *field_name)
+{
+	int i = 0;
+	while (stamp_metadata_fields[i] != NULL) {
+		if (STREQ(field_name, stamp_metadata_fields[i])) {
+			return false;
+		}
+		i++;
+	}
+	return true;
+}
+
+static void metadata_copy_custom_fields(
+        const char *field,
+        const char *value,
+        void *rr_v)
+{
+	if (!metadata_is_copyable(field)) {
+		return;
+	}
+	RenderResult *rr = (RenderResult *)rr_v;
+	BKE_render_result_stamp_data(rr, field, value);
+}
+
 void BKE_stamp_info_from_imbuf(RenderResult *rr, struct ImBuf *ibuf)
 {
 	if (rr->stamp_data == NULL) {
@@ -2185,6 +2229,8 @@ void BKE_stamp_info_from_imbuf(RenderResult *rr, struct ImBuf *ibuf)
 	struct StampData *stamp_data = rr->stamp_data;
 	IMB_metadata_ensure(&ibuf->metadata);
 	BKE_stamp_info_callback(ibuf, stamp_data, metadata_get_field, true);
+	/* Copy render engine specific settings. */
+	IMB_metadata_foreach(ibuf, metadata_copy_custom_fields, rr);
 }
 
 bool BKE_imbuf_alpha_test(ImBuf *ibuf)

source/blender/editors/include/ED_screen.h

@@ -47,6 +47,7 @@ struct bContext;
 struct bScreen;
 struct rcti;
 struct uiBlock;
+struct uiLayout;
 struct wmEvent;
 struct wmKeyConfig;
 struct wmMsgBus;
@@ -98,6 +99,7 @@ void    ED_region_visibility_change_update(struct bContext *C, struct ARegion *a
 void    ED_region_info_draw(struct ARegion *ar, const char *text, float fill_color[4], const bool full_redraw);
 void    ED_region_info_draw_multiline(ARegion *ar, const char *text_array[], float fill_color[4], const bool full_redraw);
 void    ED_region_image_metadata_draw(int x, int y, struct ImBuf *ibuf, const rctf *frame, float zoomx, float zoomy);
+void    ED_region_image_metadata_panel_draw(struct ImBuf *ibuf, struct uiLayout *layout);
 void    ED_region_grid_draw(struct ARegion *ar, float zoomx, float zoomy);
 float	ED_region_blend_alpha(struct ARegion *ar);
 void	ED_region_visible_rect(struct ARegion *ar, struct rcti *rect);

source/blender/editors/screen/area.c

@@ -2756,7 +2756,7 @@ static void metadata_draw_imbuf(ImBuf *ibuf, const rctf *rect, int fontid, const
 		for (i = 5; i < 10; i++) {
 			len = BLI_snprintf_rlen(temp_str, MAX_METADATA_STR, "%s: ", meta_data_list[i]);
 			if (metadata_is_valid(ibuf, temp_str, i, len)) {
-				BLF_position(fontid, xmin + ofs_x, ymin, 0.0f);
+				BLF_position(fontid, xmin + ofs_x, ymin + ofs_y, 0.0f);
 				BLF_draw(fontid, temp_str, BLF_DRAW_STR_DUMMY_MAX);
 
 				ofs_x += BLF_width(fontid, temp_str, BLF_DRAW_STR_DUMMY_MAX) + UI_UNIT_X;
@@ -2802,6 +2802,7 @@ static float metadata_box_height_get(ImBuf *ibuf, int fontid, const bool is_top)
 		for (i = 5; i < 10; i++) {
 			if (metadata_is_valid(ibuf, str, i, 0)) {
 				count = 1;
+				break;
 			}
 		}
 	}
@@ -2886,6 +2887,28 @@ void ED_region_image_metadata_draw(int x, int y, ImBuf *ibuf, const rctf *frame,
 	GPU_matrix_pop();
 }
 
+typedef struct MetadataPanelDrawContext {
+	uiLayout *layout;
+} MetadataPanelDrawContext;
+
+static void metadata_panel_draw_field(
+        const char *field,
+        const char *value,
+        void *ctx_v)
+{
+	MetadataPanelDrawContext *ctx = (MetadataPanelDrawContext *)ctx_v;
+	uiLayout *row = uiLayoutRow(ctx->layout, false);
+	uiItemL(row, field, ICON_NONE);
+	uiItemL(row, value, ICON_NONE);
+}
+
+void ED_region_image_metadata_panel_draw(ImBuf *ibuf, uiLayout *layout)
+{
+	MetadataPanelDrawContext ctx;
+	ctx.layout = layout;
+	IMB_metadata_foreach(ibuf, metadata_panel_draw_field, &ctx);
+}
+
 void ED_region_grid_draw(ARegion *ar, float zoomx, float zoomy)
 {
 	float gridsize, gridstep = 1.0f / 32.0f;

source/blender/editors/space_clip/clip_buttons.c

@@ -29,8 +29,9 @@
 #include "DNA_screen_types.h"
 #include "DNA_space_types.h"
 
-#include "BLI_math.h"
 #include "BLI_utildefines.h"
+#include "BLI_listbase.h"
+#include "BLI_math.h"
 #include "BLI_path_util.h"
 #include "BLI_string.h"
 
@@ -43,7 +44,9 @@
 
 #include "DEG_depsgraph.h"
 
+#include "ED_clip.h"
 #include "ED_gpencil.h"
+#include "ED_screen.h"
 
 #include "UI_interface.h"
 #include "UI_resources.h"
@@ -60,9 +63,38 @@
 
 /* Panels */
 
-void ED_clip_buttons_register(ARegionType *UNUSED(art))
+static bool metadata_panel_context_poll(const bContext *C, PanelType *UNUSED(pt))
 {
+	return ED_space_clip_poll((bContext *)C);
+}
 
+static void metadata_panel_context_draw(const bContext *C, Panel *panel)
+{
+	SpaceClip *space_clip = CTX_wm_space_clip(C);
+	/* NOTE: This might not be exactly the same image buffer as shown in the
+	 * clip editor itself, since that might be coming from proxy, or being
+	 * postprocessed (stabilized or undistored).
+	 * Ideally we need to query metadata from an original image or movie without
+	 * reading actual pixels to speed up the process. */
+	ImBuf *ibuf = ED_space_clip_get_buffer(space_clip);
+	if (ibuf != NULL) {
+		ED_region_image_metadata_panel_draw(ibuf, panel->layout);
+		IMB_freeImBuf(ibuf);
+	}
+}
+
+void ED_clip_buttons_register(ARegionType *art)
+{
+	PanelType *pt;
+
+	pt = MEM_callocN(sizeof(PanelType), "spacetype clip panel metadata");
+	strcpy(pt->idname, "CLIP_PT_metadata");
+	strcpy(pt->label, N_("Metadata"));
+	strcpy(pt->category, "Footage");
+	strcpy(pt->translation_context, BLT_I18NCONTEXT_DEFAULT_BPYRNA);
+	pt->poll = metadata_panel_context_poll;
+	pt->draw = metadata_panel_context_draw;
+	BLI_addtail(&art->paneltypes, pt);
 }
 
 /********************* MovieClip Template ************************/

source/blender/editors/space_image/image_buttons.c

@@ -1269,9 +1269,35 @@ void uiTemplateImageInfo(uiLayout *layout, bContext *C, Image *ima, ImageUser *i
 
 #undef MAX_IMAGE_INFO_LEN
 
-void image_buttons_register(ARegionType *UNUSED(art))
+static bool metadata_panel_context_poll(const bContext *C, PanelType *UNUSED(pt))
 {
+	SpaceImage *space_image = CTX_wm_space_image(C);
+	return space_image != NULL && space_image->image != NULL;
+}
 
+static void metadata_panel_context_draw(const bContext *C, Panel *panel)
+{
+	void *lock;
+	SpaceImage *space_image = CTX_wm_space_image(C);
+	Image *image = space_image->image;
+	ImBuf *ibuf = BKE_image_acquire_ibuf(image, &space_image->iuser, &lock);
+	if (ibuf != NULL) {
+		ED_region_image_metadata_panel_draw(ibuf, panel->layout);
+	}
+	BKE_image_release_ibuf(image, ibuf, lock);
+}
+
+void image_buttons_register(ARegionType *art)
+{
+	PanelType *pt;
+
+	pt = MEM_callocN(sizeof(PanelType), "spacetype image panel metadata");
+	strcpy(pt->idname, "IMAGE_PT_metadata");
+	strcpy(pt->label, N_("Metadata"));
+	strcpy(pt->translation_context, BLT_I18NCONTEXT_DEFAULT_BPYRNA);
+	pt->poll = metadata_panel_context_poll;
+	pt->draw = metadata_panel_context_draw;
+	BLI_addtail(&art->paneltypes, pt);
 }
 
 static int image_properties_toggle_exec(bContext *C, wmOperator *UNUSED(op))

source/blender/editors/space_sequencer/sequencer_buttons.c

@@ -27,10 +27,12 @@
 #include "MEM_guardedalloc.h"
 
 #include "BLI_utildefines.h"
+#include "BLI_listbase.h"
 
 #include "BLT_translation.h"
 
 #include "BKE_context.h"
+#include "BKE_global.h"
 #include "BKE_screen.h"
 
 #include "ED_screen.h"
@@ -40,6 +42,8 @@
 #include "WM_api.h"
 #include "WM_types.h"
 
+#include "IMB_imbuf_types.h"
+#include "IMB_imbuf.h"
 
 #include "sequencer_intern.h"
 
@@ -55,11 +59,51 @@ static bool sequencer_grease_pencil_panel_poll(const bContext *C, PanelType *UNU
 }
 #endif
 
-void sequencer_buttons_register(ARegionType *UNUSED(art))
+static bool metadata_panel_context_poll(const bContext *C, PanelType *UNUSED(pt))
+{
+	SpaceSeq *space_sequencer = CTX_wm_space_seq(C);
+	if (space_sequencer == NULL) {
+		return false;
+	}
+	return ED_space_sequencer_check_show_imbuf(space_sequencer);
+}
+
+static void metadata_panel_context_draw(const bContext *C, Panel *panel)
+{
+	/* Image buffer can not be acquired during render, similar to
+	 * draw_image_seq(). */
+	if (G.is_rendering) {
+		return;
+	}
+	struct Main *bmain = CTX_data_main(C);
+	struct Depsgraph *depsgraph = CTX_data_depsgraph(C);
+	struct Scene *scene = CTX_data_scene(C);
+	SpaceSeq *space_sequencer = CTX_wm_space_seq(C);
+	/* NOTE: We can only reliably show metadata for the original (current)
+	 * frame when split view is used. */
+	const bool show_split = (
+	        scene->ed &&
+	        (scene->ed->over_flag & SEQ_EDIT_OVERLAY_SHOW) &&
+	        (space_sequencer->mainb == SEQ_DRAW_IMG_IMBUF));
+	if (show_split &&
+	    space_sequencer->overlay_type == SEQ_DRAW_OVERLAY_REFERENCE)
+	{
+		return;
+	}
+	/* NOTE: We disable multiview for drawing, since we don't know what is the
+	 * from the panel (is kind of all the views?). */
+	ImBuf *ibuf = sequencer_ibuf_get(bmain, depsgraph, scene, space_sequencer, scene->r.cfra, 0, "");
+	if (ibuf != NULL) {
+		ED_region_image_metadata_panel_draw(ibuf, panel->layout);
+		IMB_freeImBuf(ibuf);
+	}
+}
+
+void sequencer_buttons_register(ARegionType *art)
 {
-#if 0
 	PanelType *pt;
 
+#if 0
 	pt = MEM_callocN(sizeof(PanelType), "spacetype sequencer panel gpencil");
 	strcpy(pt->idname, "SEQUENCER_PT_gpencil");
 	strcpy(pt->label, N_("Grease Pencil"));
@@ -69,6 +113,14 @@ void sequencer_buttons_register(ARegionType *UNUSED(art))
 	pt->poll = sequencer_grease_pencil_panel_poll;
 	BLI_addtail(&art->paneltypes, pt);
 #endif
+
+	pt = MEM_callocN(sizeof(PanelType), "spacetype sequencer panel metadata");
+	strcpy(pt->idname, "SEQUENCER_PT_metadata");
+	strcpy(pt->label, N_("Metadata"));
+	strcpy(pt->translation_context, BLT_I18NCONTEXT_DEFAULT_BPYRNA);
+	pt->poll = metadata_panel_context_poll;
+	pt->draw = metadata_panel_context_draw;
+	BLI_addtail(&art->paneltypes, pt);
 }
 
 /* **************** operator to open/close properties view ************* */

source/blender/imbuf/IMB_metadata.h

@@ -66,4 +66,8 @@ void IMB_metadata_set_field(struct IDProperty *metadata, const char *key, const
 void IMB_metadata_copy(struct ImBuf *dimb, struct ImBuf *simb);
 struct IDProperty *IMB_anim_load_metadata(struct anim *anim);
 
+/* Invoke callback for every value stored in the metadata. */
+typedef void (*IMBMetadataForeachCb)(const char *field, const char *value, void *userdata);
+void IMB_metadata_foreach(struct ImBuf *ibuf, IMBMetadataForeachCb callback, void *userdata);
+
 #endif /* __IMB_METADATA_H__ */

source/blender/imbuf/intern/metadata.c

@@ -102,3 +102,10 @@ void IMB_metadata_set_field(struct IDProperty *metadata, const char *key, const
 
 	IDP_AssignString(prop, value, METADATA_MAX_VALUE_LENGTH);
 }
+
+void IMB_metadata_foreach(struct ImBuf *ibuf, IMBMetadataForeachCb callback, void *userdata)
+{
+	for (IDProperty *prop = ibuf->metadata->data.group.first; prop != NULL; prop = prop->next) {
+		callback(prop->name, IDP_String(prop), userdata);
+	}
+}